The linear sweep of a frequency over a range of frequencies to encounter an unknown signal lobing frequency expected from an enemy passive sequential lobing radar to detect and repeat back the radar frequency at the pulse repetition rate to deceive is well known in the radar countermeasures art. Silent sequential lobing radars do not reveal their lobing rate in their transmission, and therefore the countermeasure equipment must sweep through the entire possible range of lobing rates. If the frequency of the countermeasure modulation is swept slowly enough to cause break lock when the correct frequency is reached, the length of time spent at the wrong frequency may be excessive.